mds: allow sending MMDSFindIno to MDS who is in clientreplay state

Because MDCache::kick_find_ino_peers() is called when a MDS enters
clientreplay state.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: don't increase nlink when rollback stray reintegration

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>